Violet-blue vat dyestuffs.



UNITED sratr si gnn'r orrion.

nnwm HOFFA, or noonsr-on-rna-mam, GERMANY, ASSIGNOR TO rAnawnnKE vomu'. MEIS'IER LUCIUS & BRUNING, or HooHs'r-oNaHn-Iaam, GERMANY, A

CORPORATION OF GERMANY.

VIOLET-BLUE VAT DYESTUFFS.

E0 Drawing.

whereinR stands for an alkyl group, H al for a halogen, namely chlorin or bromin. These coloring matters are obtained by the known rocesses, for instance from the thioglycolhc acid of the constitution:

by the action of 'chlorosulfonic acid. The same coloring matters can also be produced by oxidizin the corresponding substituted oxy-thionap thenes obtainable according to the methods used in the thioindigo series. It is surprising that these dyestufi's dye in the vat violet-blue tints, because the isomeric dyestuffs:

v wherein the chlorin is in 6 position, dye

bluish-red tints.

The following example illustrates my in-.

vention: One part of thioglycollic acid of the constitution;

is introduced at about 15 G. into 5 parts of chlorosulfonic acid, and the mixture is stirred until the formation of the dyestufi" The dyestufi', forms a violet-blue powder" which is insoluble in water, almost insoluble Specification of Letters Patent.

Patented May 7, 1912.

Application filedOctober 26, 1910. Serial No. 589,160.

in alcohol to a violet solution, soluble in hot nitrobenzene to a violet, and in concentrated sulfuric acid to a green solution. On adding a solution of alkaline hydrosulfite it gives a yellow vat, which dyes cotton and wool violet-blue, fast tints.

If instead of the above-mentioned methoxylated thioglycollic acid the corresponding ethoxylated acid is used, a very similar dyestufl is obtained. The corresponding bromin-substituted 'dyestuif also very muicfh resembles the above described dyestu I Having now described my invention what I claim is:

1. ,Asnew products, the bluish-violet vat dyestufls of the constitution:

CI-Ia\ co, 2 2 (:0 0H, 4 g x cns S )0 o S onn g 1 Y ,I wherein Hal means a halogen and R n" alkyl, being a violet-blue powder, insoluble in water, almost insoluble in alcohol, soluble in nitrobenzene to a violet solution, in concentrated sulfuric acid to a green solution, yielding on addition of a solution of alkaline hydrosulfite a yellow vat which dyes cotton and wool violet-blue tints.

2. As a new product, a bluish-violet vat dyestufi' of the constitution:

4 on iiii {2 (2) on 4 4 5 c1 ---cu o=o a 01 r hi omo s s oon, ii

being a violet-blue powder, insoluble in water, almost insoluble in alcohol, soluble in nitrobenzene to a violet solution, in concentrated sulfuric acid to a green solution, yielding on addition of a solution of alkaline hydrosulfite a yellow vatwhieh dyes cotton and Wool violet-blue tints.

In testimony whereof, I affix my signathre'in presence of two witnesses.

ERWIN HOFFA.

Witnesses JEAN GRUND, CARL Gem. 

